refactor: implement component-based architecture for enhanced maintainability

- Reorganize directory structure into core/, features/, and themes/
- Colocate application Nix logic, configs, scripts, and theme overrides
- Implement 'Inversion of Control' for theming: apps now pull theme-specific layouts
- Update flake.nix and shared library paths to match the new structure
- Document the new Feature-Centric architecture in README.md

features/scripts/utils/nomarchy-drive-select

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# Select a drive from a list with info that includes space and brand. Used by nomarchy-drive-set-password.
+
+if (($# == 0)); then
+  drives=$(lsblk -dpno NAME | grep -E '/dev/(sd|hd|vd|nvme|mmcblk|xv)')
+else
+  drives="$@"
+fi
+
+drives_with_info=""
+while IFS= read -r drive; do
+  [[ -n $drive ]] || continue
+  drives_with_info+="$(nomarchy-drive-info "$drive")"$'\n'
+done <<<"$drives"
+
+selected_drive="$(printf "%s" "$drives_with_info" | gum choose --header "Select drive")" || exit 1
+printf "%s\n" "$selected_drive" | awk '{print $1}'